In recent years, the harvesting industry has developed combines in which rotors and cooperating concaves have been disposed axially within the threshing compartment of the combine for purposes of receiving at the forward end material to be threshed and discharge the separated waste material, such as chaff, straw, vines, and the like at the rear end of the combine. Certain of these combines have had only a single rotor and concave, and others have had multiple rotors and corresponding concaves for each rotor. At present, however, there appears to be a need for a relatively simple combine having a single rotor but, normally, it has been found that if a single rotor is employed in association with a concave in the threshing compartment, there is a tendency for the threshed material to discharge through the concave in a manner to dispose the majority of the material adjacent one side of the means which receives the material for further processing, such as separating the desired material from chaff and the like. This is undesirable because of placing an excess burden upon the subsequent cleaning and separating means associated with the means to receive the threshed material and thereby decreases the efficiency of the combine.
In accordance with the principles of the present invention, it has been found that if the rotor and associated concave are disposed in an offset position to one side of the central axis of the threshing compartment, a marked improvement in the distribution of the discharge of the threshold material has been found, especially by employing appropriate deflecting means described in detail hereinafter. Such an arrangement discharges the threshed material onto the receiving means in a substantially even manner but not necessarily even in depth since there is a tendency for the material to be somewhat mounded along the longitudinal center line of the receiving means, but, nevertheless, represents a great increase in efficiency of a combine of this type.
The only prior art which has been found thus far to disclose an offset rotor for any purpose is found in the following patents: U.S. Pat. No. 3,228,176 to Stout et al., shows a conical threshing rotor which is mounted somewhat offset from the center of the threshing mechanism when viewed in plan, but a divided grain receiver is employed and no purpose is recited for what appears to be at least a slight offset of the rotor in plan view. In addition, the axis of the rotor extends downwardly at an angle as distinguished from being substantially horizontal.
Philippine Pat. No. UM 1379 shows a threshing rotor which is offset from the central axis of the frame which supports it, but without explanation for the purpose of such arrangement, and the means to receive the threshold grain has an auger which carries the threshed product toward the rear where it is sifted by a rotating screen. Neither is the combine of the axial flow type, since the material to be threshed is introduced through one side of the threshing compartment which would tend to indicate that the combine is not of the mobile type in the same sense as conventional mobile combines.